1. Field of the Invention
The present invention relates to a process for pressing folded printing products and an apparatus for carrying out the process.
2. Description of the Related Art
In order to ensure a reliably safe further processing of folded printing products which are usually delivered in an imbricated formation, it is often necessary to press these printing products, in particular in order to compress the printing products in the region of the folded edge, the so-called back of the printing product, where they are thicker and "lighter" because of the fold. In the process, the printing products, overlapping each other in the manner of roof tiles, viewed in the conveying direction, are usually fed with folded edges running at right angles to the conveying direction and side edges aligned with one another to a pressing nip defined by two pressing rolls pretensioned toward one another and whose inlet runs parallel to the folded edges, in other words at right angles to the conveying direction. The thickness of the imbricated formation thus alters abruptly along the entire width of the imbricated formation, which results in an unsmooth pressing process. The thickness of the pressing nip must be adapted to these large changes in thickness of the imbricated formation fed to it. This may result in the printing products being inadequately pressed in the region of the folded edges and in the pressing rolls not running smoothly.